Lactobacilli isolated from vaginal vault of dairy and meat cows during progesteronic stage of estrous cycle

Abstract

Lactobacilli have been barely studied in cows. We proposed isolate and characterize lactic acid bacteria from dairy cows as compared to those raised for meat production and elucidate the presence of strains with evident probiotic employment’s potential. For this, isolation and quantification of LAB mainly lactobacilli were realized from vaginal cattle samples in MRS medium. Each selected microorganism was then briefly characterized. The MATH method was employed using hexadecane, xilene an toluene as solvent. According to the hydrophobic characteristics, strains were classified into three categories: high (71–100%), medium (36–70%) and low (0–35%). Hydrogen peroxide qualitative production was studies too, lactobacilli were streaked onto an MRS agar plate containing 5 mg of 3,3′,5,5′-tetramethylbenzidine and 0.20 mg of horseradish peroxidase. Twenty-one sampled cows (78%) were positive for lactic acid microflora, 12 belonging to the dairy group and 17 of the meat group. Total LAB counting including dairy and meat cows were log 2,41 CFU/ml. Of overall identified strains, an 83% corresponded to lactobacilli. Most strains belonged to the heterofermentative facultative group (75%), with L. plantarum as the most frequent specie. The highest proportion of isolated vaginal strains (69%) had low hydrophobicity, the LAB with highest hydrophobic characteristics (3 strains) were found only in meat cows. In the qualitative evaluation of H 2O 2 production, a positive reaction was observed in 13 of 29 strains (45%). The role of lactobacilli in vaginal microbiota is limited, and therefore the present work is interesting in incorporate knowledge of normal microflora of progesteronic healthy cows, in this case in production animals. The isolation and characterization data obtained are consistent in consider the study of particular strains with great potential in the development of a probiotic for production cows.